1,618 research outputs found

    Non-Stationary Random Process for Large-Scale Failure and Recovery of Power Distributions

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    A key objective of the smart grid is to improve reliability of utility services to end users. This requires strengthening resilience of distribution networks that lie at the edge of the grid. However, distribution networks are exposed to external disturbances such as hurricanes and snow storms where electricity service to customers is disrupted repeatedly. External disturbances cause large-scale power failures that are neither well-understood, nor formulated rigorously, nor studied systematically. This work studies resilience of power distribution networks to large-scale disturbances in three aspects. First, a non-stationary random process is derived to characterize an entire life cycle of large-scale failure and recovery. Second, resilience is defined based on the non-stationary random process. Close form analytical expressions are derived under specific large-scale failure scenarios. Third, the non-stationary model and the resilience metric are applied to a real life example of large-scale disruptions due to Hurricane Ike. Real data on large-scale failures from an operational network is used to learn time-varying model parameters and resilience metrics.Comment: 11 pages, 8 figures, submitted to IEEE Sig. Pro

    Sparse-matrix Representation of Spiking Neural P Systems for GPUs

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    Current parallel simulation algorithms for Spiking Neural P (SNP) systems are based on a matrix representation. This helps to harness the inherent parallelism in algebraic operations, such as vector-matrix multiplication. Although it has been convenient for the rst parallel simulators running on Graphics Processing Units (GPUs), such as CuSNP, there are some bottlenecks to cope with. For example, matrix representation of SNP systems with a low-connectivity-degree graph lead to sparse matrices, i.e. containing more zeros than actual values. Having to deal with sparse matrices downgrades the performance of the simulators because of wasting memory and time. However, sparse matrices is a known problem on parallel computing with GPUs, and several solutions and algorithms are available in the literature. In this paper, we brie y analyse some of these ideas and apply them to represent some variants of SNP systems. We also conclude which variant better suit a sparse-matrix representation

    Empowering the Indiana Bridge Inventory Database Toward Rapid Seismic Vulnerability Assessment

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    With the recent identification of the Wabash Valley Seismic Zone in addition to the New Madrid Seismic Zone, Indiana’s Department of Transportation (INDOT) has become concerned with ensuring the adequate seismic performance of their bridge network. While INDOT made an effort to reduce the seismic vulnerability of newly-constructed bridges, many less recent bridges still have the potential for vulnerability. Analyzing these bridges’ seismic vulnerability is a vital task. However, developing a detailed dynamic model for every bridge in the state using information from structural drawings is rather tedious and time-consuming. In this study, we develop a simplified dynamic assessment procedure using readily-available information from INDOT’s Bridge Asset Management Program (BIAS), to rapidly identify vulnerable bridges throughout the state. Eight additional data items are recommended to be added into BIAS to support the procedure. The procedure is applied in the Excel file to create a tool, which is able to automatically implement the simplified bridge seismic analysis procedure. The simplified dynamic assessment procedure and the Excel tool enable INDOT to perform seismic vulnerability assessment and identify bridges more frequently. INDOT can prioritize these bridges for seismic retrofits and efficiently ensure the adequate seismic performance of their assets

    Cislunar Explorers: Lessons Learned from the Development of an Interplanetary CubeSat

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    The Cislunar Explorers mission is a pair of ~3U nanosatellites (named Hydrogen and Oxygen) launching as a single 6U CubeSat as part of NASA’s Artemis-1 mission on the Space Launch System (SLS). The two spacecraft will demonstrate technologies increasing the reach, flexibility, and cost-effectiveness of interplanetary smallsats. These innovations include water electrolysis propulsion, multi-body optical navigation, passive spin-stabilization, and the operation of femtosatellites beyond low earth orbit. Cislunar Explorers also serves as a pathfinder for demonstrating the utility and versatility of water for future In Situ Resource Utilization (ISRU) on space missions. Critical subsystems complement each other to reduce the cost and complexity. Water not only serves as the propellant for the propulsion system, but also as a radiation shield, electronics heat sink, and nutation damper. Each spacecraft’s spin provides attitude stabilization, separates electrolyzed gas from the water in the propulsion tank, simplifies the active attitude control system, and enables the optical navigation system to cover a panoramic view around the spacecraft. The unique elements of the mission spacecraft’s design provided advantages to traditional CubeSat architectures but also produced unexpected development challenges. By leveraging the lessons learned from the development of the Cislunar Explorers mission, future interplanetary missions can utilize its technology to reduce cost, risk, and complexity

    Uso y desecho de medicamentos del botiquĂ­n familiar desde la educaciĂłn ambiental

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    The objective of the study was to describe the use and disposal of medicines from the family medicine cabinet from the perspective of environmental education. The study was conducted from January to October 2022 with 72 students of the Pharmacy and Biochemistry academic program of the Universidad Nacional “San Luis Gonzaga”, Ica, Peru. A virtual survey was applied using Google form with nine questions where the descriptive statistician was the relative trend analysis of the percentage. Storage in the medicine cabinet represented the highest percentage: 46.94%. The 10.20% of students did not know that medicines contaminate and 18.37% did not know that medicine wastes are harmful to health when consumed by animals and transferred to humans. A total of 6.12% of the students did not know that there are medicine containers and 14.29% of the students disposed of medicines inappropriately at home, where the highest percentage of disposal was for expiration and non-consumption: 46.94%. Annual disposal was the highest percentage (42.86%) and is produced by crushing (95.92%), where antibacterials were the therapeutic group with the highest frequency of disposal (46.95%) and antibiotics the lowest (2.04%). It is concluded that it is necessary to implement an environmental education on the disposal and elimination of medicines from the family medicine cabinet for university students, since there was a lack of knowledge about their storage, elimination and impact on public health and the environment.El objetivo del estudio fue describir el uso y desecho de medicamentos del botiquĂ­n familiar desde la educaciĂłn ambiental. El estudio se realizĂł de enero a octubre de 2022 con 72 estudiantes del programa acadĂ©mico de Farmacia y BioquĂ­mica de la Universidad Nacional “San Luis Gonzaga”, Ica, PerĂș. Se aplicĂł, una encuesta virtual mediante “Google form” con nueve preguntas donde el estadĂ­grafo descriptivo fue el anĂĄlisis de tendencia relativa del porcentaje. El almacenamiento en el botiquĂ­n representĂł el mayor porcentaje: 46,94%. El 10,20% de los estudiantes, desconoce que los medicamentos contaminan y el 18,37%, tampoco conoce quĂ© los desechos de medicamentos al consumirse por animales y transferirse al humano dañan la salud. El 6,12% de los estudiantes, no conoce que existen contenedores de medicamentos y se registrĂł que el 14,29% los elimina inadecuadamente en el hogar donde el mayor porcentaje de eliminaciĂłn fue para el vencimiento y no consumo: 46,94%. La eliminaciĂłn anual fue el porcentaje mayor (42,86%) y se produce por trituraciĂłn (95,92%), donde los antibacterianos fueron el grupo terapĂ©utico con mayor frecuencia de eliminaciĂłn (46,95%) y los antibiĂłticos el menor (2,04%). Se concluye, que se requiere implementar una educaciĂłn ambiental ante la disposiciĂłn y desecho de medicamentos del botiquĂ­n familiar para los estudiantes universitarios, pues existiĂł desconocimiento desde su almacenamiento, eliminaciĂłn e impacto a la salud pĂșblica y el medio ambiente

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+→Ό+ÎœW^+ \rightarrow \mu^+\nu and W−→Ό−ΜW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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